//
//  CZNewFeatureViewController.swift
//  iOSWeibo10
//
//  Created by ge on 16/5/14.
//  Copyright © 2016年 ge. All rights reserved.
//

import UIKit

private let reuseIdentifier = "Cell"
private let ItemCount = 4

class CZNewFeatureViewController: UICollectionViewController {
    
    // MARK: - 属性
    /// layout
    private let layout = UICollectionViewFlowLayout()
    
    init() {
        super.init(collectionViewLayout: layout)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        
        prepareCollectionView()
    }
    
    private func prepareCollectionView() {
        // 注册cell
        self.collectionView!.registerClass(CZNewFeatureCell.self, forCellWithReuseIdentifier: reuseIdentifier)
        
        // 设置layout参数
        // 让cell和屏幕一样大
        layout.itemSize = UIScreen.mainScreen().bounds.size
        //水平滚动
        layout.scrollDirection = UICollectionViewScrollDirection.Horizontal
        //间距
        layout.minimumInteritemSpacing = 0
        layout.minimumLineSpacing = 0
        //取消弹簧效果
        collectionView?.bounces = false
        //不要水平滚动条
        collectionView?.showsHorizontalScrollIndicator = false
        //分页
        collectionView?.pagingEnabled = true
    }
}

extension CZNewFeatureViewController {
    // 某一组显示几个cell
    override func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
        return ItemCount
    }
    
    // 每个cell张什么样
    override func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        // 直接取cell
        // dequeueReusableCellWithReuseIdentifier: 取cell会先去缓存池中取cell,缓存池中取不到会使用注册的cell来创建
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier(reuseIdentifier, forIndexPath: indexPath) as! CZNewFeatureCell
        
        cell.backgroundColor = UIColor.brownColor()

        // 设置cell显示的index
        cell.index = indexPath.item
        // 在这里设置按钮的动画不合适,在collectionView停止滚动的时候在做动画
//        cell.startAnimation()
        
        return cell
    }
    
    /// scrollView停止滚动
    override func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
        // 获取collectionView的偏移值,计算出当前停下来的是哪一页
        let index = Int(scrollView.contentOffset.x / scrollView.frame.width)
//        CZPrint(items: "scrollView停止滚动, 在第 \(index) 页")
        
        // 判断是否是最后一页
        if index == ItemCount - 1 {
            // 获取cell,千万不要自己去创建cell,应该拿到正在显示的cell
            let indexPath = NSIndexPath(forItem: index, inSection: 0)
            let cell = collectionView?.cellForItemAtIndexPath(indexPath) as! CZNewFeatureCell
            cell.startAnimation()
        }
    }
}



















